Electron capture processes of Iq+ions with very high charge states (41⩾q⩾10) in collisions with He atoms

One-electron capture processes of iodine (I q+ ) ions with very high charge q up to 41 in collisions with He atoms at low energies have been investigated using energy gain spectroscopy. It is found that total cross sections increase with increasing charge of ions q, and also increase roughly with the square of the crossing radius R c of the diabatic potential curves in the quasi-molecules where the electron transfer takes place. This smooth variation, in contrast to that in ions with low charge where only few crossings play a role, can be understood from the fact that a number of the crossings closely located in a relatively narrow region of R c contribute to the one-electron transfer processes in ions with high charge.